Failure of the exhaust gas centrifugal compressor
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In my workshop, the exhaust compressor stopped operating due to high shaft displacement temperature; the rotational speed rose to the rated level and the load reached around 60 percent. There were small particles in the lubricating oil that could be felt by touch. After several reassemblies, there was slight wear on the lower surface caused by Kingsbury’s pushing force, but there were grooves on the temperature probe grate resulting from wear by the balance discs. The unit is arranged as turbine + high-pressure compressor cylinder + low-pressure compressor cylinder. Could you please analyze whether the stiffness of the bearing oil film might be too low, whether there are excessive mechanical impurities in the oil, and whether the cause of the temperature-related shutdown is related to problems with the bearing pads, oil pressure, or balance? Thank you so much!
In such cases, the entire lubrication system needs to be cleaned; in particular, the filters must be replaced multiple times, and a long-term circulation of the oil is necessary. If debris can be felt by hand, the main issue should first be addressed by improving the quality of the oil. Then proceed with the measurement of the shaft bearings, the measurement of the couplings, and the cleaning of the surfaces that have been ground. In addition, factors such as the degree of scaling on the impeller and dynamic balance also need to be checked.
“However, the temperature probe grate has grooves caused by wear from the balance disc. ”What does that mean? There must be a problem with the quality of the oil
Analyze the oil parameters: cleanliness, praseodymium analysis.
1. The presence of particulate matter in lubricating oil is highly abnormal; it requires analysis and filtration. 2. The temperature probe has been scratched by the balancing disk (I’m not sure if this is the correct way to describe it); photos are needed to conduct an accurate analysis. 3. Is the shaft displacement out of tolerance?
From the axis position diagram, at the front support bearing of the high-pressure cylinder, the axis exceeds the clearance circle at the critical speed and deviates by about 60°; on the polar coordinate diagram, there are only straight lines connecting the high points, with no circular shapes shown